Industrial truck attachment



A ril 21, 1964 w. J. TOWNSEND 3,129,833

INDUSTRIAL TRUCK ATTACHMENT Filed Dec. 29, 1960 4 Shets-Sheet 1 INV ENTOR.

WALTER J. TOWNSEND BY ATTORNEY April 1964 w. J. TOWNSEND 3,129,833

INDUSTRIAL TRUCK ATTACHMENT Filed Dec. 29, 1960 4 Sheets-Sheet 2 FIG. 2'04 v mmvron WALTER J. TOWNSEND ATTORNEY April 1964 w. J. TOWNSEND3,129,833

INDUSTRIAL TRUCK ATTACHMENT Filed Dec. 29, 1960 4 Sheets-Sheet 3 FIG. 67

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4 Sheets-Sheet 4 FIG. 5

SH N 1 L INVENTOR. WALTER J. TOWNSEND BY ATTORNEY United States Patent3,129,333 INDUSTRIAL TRUCK ATTACHMENT Walter J. Townsend, Delton, Mich,assignor to Clark Equipment Company, a corporation of Michigan FiledDec. 29, 1960, Ser. No. 79,200 2 Claims. (Cl. 214-317) My presentinvention relates generally to a load elevating and dumping mechanism,and more specifically is directed to a lift dump attachment particularlyadapted for emptying tote trays and the like.

It is an object of the present invention to provide an improved liftdump attachment construction which is well suited for use withindustrial lift trucks, for example.

Another object of the invention is to provide a lift dump attachmentwhich is of simple and economical construction, relatively free ofservice and maintenance costs, and economical and eflicient inoperation.

A further object of the invention is to provide a lift dump attachmentfor lift trucks in which a tote tray or other material handling dump boxis continuously engaged during elevation thereof on the upright of thetruck and which is actuatable to a dump position from an elevatedposition on the upright by the combined use of means adapted to connecta portion of the tote tray to a telescoping portion of the upright andload engaging means of the truck which effect dumping of the tote trayas it is lowered in the upright at a rate greater than the lowering ofthe telescoping portion of the upright.

The lift dump attachment of my present invention comprises a frame meanswhich is adapted to be secured to the load supporting fork carriage of alift truck in which the fork carriage is supported in the usual mannerfor elevating movement in a telescoping upright construction of thetruck. An inner sliding frame member of the frame means carries a totetray engaging element adjacent the bottom thereof and is mounted forsliding movement in the frame means. The inner sliding member includesan opening therethrough at a predetermined location and is preferablylocated on the fork carriage intermediate a pair of fork tines which arealso carried thereby. A latch mechanism is mounted atop the telescopingportion of the upright construction, and upon elevation of the forkcarriage and attachment in the upright to a predetermined height thelatch is actuatable to engage the opening in the inner sliding member ofthe frame means which causes the fork tines to move downwardly away fromthe inner sliding member upon lowering of the upright. Such loweringmovement causes the fork tines to be lowered at a 2:1 ratio relative tothe upright in the embodiment disclosed herein, which causes the totetray to tip to a dump position as the inner sliding member telescopesoutwardly of the frame means. Following dumping of the tote tray thefork tines may then be re-elevated to re-engage fully the tote tray,whereupon the latch mechanism is actuated to disengage the inner slidingmember, and the attachment and fork tines may thereupon be lowered tofloor level to repeat the aforesaid operation.

Other objects, advantages and features of the invention will becomereadily apparent from the following detailed description taken inconjunction with the drawings, wherein:

FIGURE 1 is a view in side elevation showing the lift dump attachmentmounted upon an upright mast of an industrial lift truck preparatory toengaging a tote tray;

FIGURE 2 is a front elevational view of FIGURE 1 with the tote trayremoved;

FIGURE 3 is an enlarged partial plan view of FIG- UM 2;

FIGURE 4 is a side view in elevation showing the attachment in maximumelevated position on the mast preparatory to dumping the tote tray;

3,129,833 Patented Apr. 21, 1964 FIGURE 5 is a View similar to FIGURE 4with the attachment actuated to a dumping position;

FIGURE 6 is a side view in elevation of the latching mechanism; and

FIGURE 7 is a front view of FIGURE 6.

Referring now to the drawings in detail and first to FIGURES 1-3, thefront chassis portion of an industrial lift truck is indicated generallyat numeral lid; it includes a body portion 12 mounted on an axle of apair of front drive wheels 14 and having a steering post 16 extendingupwardly into an operators compartment from an instrument panel and cowlsection 18. A vertically disposed telescopic mast structure 29 ismounted in known manner on the drive axle and is adapted to be pivotedthereon in either direction by hydraulic tilt motors, not shown, whichare connected to the mast 21) by brackets, one of which is shown at 21.

Mast structures of the type indicated are known and need not bedescribed in detail herein. Generally the mast structure includes anouter guideway formed by a pair of laterally spaced channel members 22and an inner slide structure which telescopes within the outer guidestructure and which is formed by a pair of laterally spaced channelbeams 24 nested within the outer guide structure. Transverse plate means25 connects beams 24 together at the upper end thereof and a bracket 27(FIGURE 3) connects together outer channel members 22 intermediate theends thereof.

The attachment of my invention, indicated generally at numeral 26, alongwith a pair of fork tines 23, is supported for vertical movement withinthe inner slide structure 24 by means of a known bracket, roller andload carriage assembly 30. The load carriage assembly 30 is supported inthe inner slide structure 24 for elevating movement along the mast inknown manner and is operatively connected to a hydraulic hoist cylinderand piston motor means 32 by means of lifting chains 34 which areanchored relative to the truck it) at the one end and are connected tothe carriage 30 at the other ends, being reeved over sprockets 35 whichare secured to a crosshead 36 of motor means 32. The cross-head 36 ismounted at the upper end of the piston rod and is secured by bolts 33 toplate means 25 of the inner slide structure 24. Extension and retractionof the piston rod raises and lowers the load carriage 3i? relative tothe inner slide 24 by means of chains 34 and the inner slide relative tothe outer channel members 22 in a Well-known manner. The attachment 26is supported upon the load carriage 3% by a plurality of bolts 4-2 andextends upwardly therefrom intermediate the fork tines 28.

The lift dump attachment 26 comprises a built-up channel construction 44which includes a transverse, vertically extending rear plate member 46,and a pair of transversely spaced, vertically extending plates 48connected to the transverse plate 46 by intermediate plates 50. Adownwardly extending slot 52 is formed in the back plate 46. A slideplate 54 is nested in channel assembly 44 and extends a short distancebelow the channel assembly when fully nested therein. Slide plate 54 hassecured to the forward surface thereof a pair of upper and lowertransversely spaced slide bars 56, a C-shaped hook member 58 mounted atthe lower end of the slide plate, and a rectangular opening 60 formedcentrally of the slide plate and at a predetermined distance from theupper end thereof. The opposite side edges of slide plate 54 each has anelongated recess 62, the length of which determines the distance whichthe slide plate can move outwardly of channel assembly 44, pins 64 beingprovided which extend through the channel assembly for supporting theslide plate fully nested Within the channel assembly when in abutmentwith the upper shoulders of recesses 62 and limiting the extent ofoutward movement of the slide plate relative to the channel assemblywhen in contact with the lower shoulders of recesses 62.

A manually actuatable latch assembly 76 (FIGURES 6 and 7) is mounted onupper plate means 25 of inner slide 24 by means of a bracket assembly'72 which comprises a pair of upright support members 74 supporting alongitudinally extending, foursided box-like assembly having side plates76 and upper and lower plates 78 forming an opening 80 in which ismounted for reciprocation an elongated bar $2. A plate 84 is located atthe forward end of bar 82 and projects slightly above the upper side ofbar 82. A manually actuated lever 86 extends through an opening %8 inthe upper plate 78 and into a vertical slot t of sliding bar $2 forconnection with a pin 92 which is supported in a transverse opening 94of the sliding bar 82. The lever arm 86 is supported pivotally from apin 96 which is supported in a pair of transversely spaced supportblocks 98 located on upper plate '78, the lever arm being normally heldin the position illustrated in FIGURES 1 and 6 by means of a tensionspring 100 which is connected to the lever arm and to an anchor block162 on upper plate 78. A crank arm 104 is connected to lever arm $6 andextends rearwardly therefrom, having a pull cable 1% extendingdownwardly thereof for actuation by the operator of the truck when it isdesired to actuate the slide bar 32 forwardly from the FIGURE 6 positionthereof to the position thereof in FIGURES 4 and for a purpose to beexplained.

A tote tray shown generally at numeral 119 may be of any suitableconstruction; as shown it comprises a lower inverted U-shaped floorsection 112 adapted to receive in the pocket thereof the fork tines 28.A three-sided plate construction comprising a rear vertical plate 116, alower horizontal plate 11% and a forwardly biased plate 120 is securedto floor section 112. Tote tray 110 is adapted to handle various typesof material, such as bar stock 122. Extending rearwardly of each side ofthe tote tray is a bracket member 124. A bar 126 extends transverselyand rearwardly of the tote tray and is secured to the ends of brackets124. The bar 126 is adapted to be engaged by the lower hook section ofC-shaped member 58 during elevation of carriage St) in mast prior to adamp operation, and by the upper hook section during elevation followinga dumping operation, as will be explained.

In operation, the industrial truck 10 is driven into position endwise oftote tray 11% until fork tines 28 are projected fully beneath the floorsection 112 of the tote tray, whereupon the hydraulic hoist motor 32 isenergized to elevate the inner slide structure 24 outwardly of outerguides 22 and to elevate attachment 26 and fork tines 28 with loadcarriage 30 in inner slide structure 24. It will be noted that C-shapedmember 58 is located at floor level when the forks are so located, andthe C-shaped member will first engage bar 126 of the tote tray as thefork tines come into abutment with the lower surface of floor section112. Continued energization of the hydraulic hoist motor 32 elevates theattachment and tote tray with the load carriage 34) in inner slidestructure 24 at a 2:1 ratio relative to the inner slide until apredetermined elevation is reached such as is shown in FIGURE 4. At thispredetermined elevation the opening 60 of slide plate 54 is in alignmentwith slide bar 82 of latch mechanism 70, whereupon the operator, withoutmoving from his seat on the lift truck, can actuate pull cable 106 andlever arm 86 to move slide bar 82 forwardly into registry and throughopening 60, as shown in FIGURE 4. With the attachment and latchingmechanism so located, the hydraulic hoist motor may then be de-energizedpermitting the load carriage, fork tines and channel assembly 44 to belowered a predetermined amount by chains 34 relative to inner slidestructure 24, while the slide plate 54, C-member 58 and tote tray bar126 are lowered with the slide bar 82 and plate of inner slide structure24. It will be noted that face plate 84 of slide bar 82 projectsslightly above the upper boundary of opening 60 thereby positivelyretaining slide plate 54 in fixed relation to the inner slide duringsuch lowering movement. Inasmuch as the load carriage 30 is lowered at a2:1 speed ratio relative to the inner slide, the forward end of the totebox, being supported on the fork tines, will be lowered away from thebar 126 thereof which is supported by the C-member 58, thus causing thetote tray 110 to be actuated from the FIGURE 4 position to a dumpposition as shown in FIG- URE 5. During such relative downward movementof the fork tines relative to O-member 58 it will be understood, ofcourse, that the inner slide plate 54 is actuated upwardly out ofchannel assembly 44 as in FIGURE 5. It will be noted that pins 64 limitthe maximum elevation of slide plate 54 outwardly of channel assembly 44at the position in which pins 64 contact the lower ends of recesses 62in the slide plate. The lift truck has in the meantime been driven to alocation wherein it is desired to discharge the load 122 from the totetray, which is accomplished when the parts of the construction arelocated as illustrated in FIGURE 5 with the mast 20 tilted slightlyforwardly by the tilt cylinders and brackets 21.

Subsequent to discharge of the load from the tote tray the hoist motor32 is re-energized to again elevate the load carriage and fork tines tothe FIGURE 4 position wherein the fork tines are again in fullengagement with the floor section 112 of the tote tray. During suchupward movement of the fork tines relative to C-mernber 58, bar 126 ofthe tote tray tends to be elevated with the rear section of the tray inrelation to the G-member. The upper hook section of C-member 58 preventsany such substantial upward relative movement of the rear section of thetray. When the attachment has been re-elevated to the FIGURE 4 position,the pull cable is released by the operator which permits spring toreturn slide bar 82 to its original position in the latching mechanism70 and out of registry with opening 6% and the slide plate 54 is againfully nested within channel assembly 44. The hoist motor is then againde-energized whereupon the load carriage, fork tines, attachment 26 andtote tray are lowered together at a 2:1 ratio in the inner slide tofloor level position, at which the lift truck may disengage itself fromthe tote tray and re-engage a second loaded tote tray to repeat theabove operation. Throughout the operation of my invention it will benoted that C-member 58 is continuously engaging support bar 126 of thetote tray, thereby assuring that the tote tray will be stably supportedagainst movement longitudinally of the fork tines.

It will now be appreciated that I have provided a novel lift truck dumpattachment construction which is relatively simple, economical inmanufacture, operation and maintenance, and extremely efiicient and safein operation.

Now, while I have shown and described what I believe to be the preferredembodiment of my present invention, it will be understood that variousmodifications and rearrangements may be made therein without departingfrom the spirit and scope of my invention.

I claim:

1. In an industrial truck having an outer fixed upright mounted at oneend of the truck, an inner movable upright telescopical within the outerfixed upright, motor means for elevating the movable upright in thefixed upright and a load supporting carriage mounted in the movableupright for raising and lowering movement relative thereto, thecombination comprising a latching mechanism mounted on the movableupright having a manually actuatable lever and a movable member adaptedto be reciprocated thereby, a pair of transversely spaced fork tinesmounted upon the load supporting carriage and adapted to be lowered tofloor level in the movable upright, and an auxiliary upright mounted onsaid load supporting carriage intermediate said fork tines having afixed portion secured to the load supporting carriage, a slidableportion mounted in the fixed portion and elevatable relative thereto, anopening in the slidable portion and a load engaging member secured onsaid slidable portion and located continuously horizontally adjacentsaid fork tines during upward and downward movement of the loadsupporting carriage in the upright except during downward movement ofthe load engaging means from an elevated position wherein said latchingmechanism engages said opening, said load supporting carriage, forktines and auxiliary upright being elevatable in said movable upright toa height at which the reciprocable member of said latching mechanism isregistrable with said openmg.

2. In an industrial truck having an outer fixed upright mounted at oneend of the truck, an inner movable upright telescopical within the outerfixed upright, motor means for elevating the movable upright in thefixed upright and a load supporting carriage mounted in the movableupright for raising and lowering movement relative thereto, thecombination comprising latching means secured to the movable upright,load engaging means projecting from the load supporting carriage, and anauxiliary upright assembly mounted on the load supporting carriage andextending upwardly therefrom including an outer fixed assembly, an innerslide assembly having means engageable with said latching means and aload engaging member projecting therefrom in normally horizontaladjacent relation to said load engaging means, said auxiliary uprightassembly being of substantially less collapsed height than said outerand inner uprights and being elevatable in the inner movable upright toa location wherein said latching means is actuatable to engage saidinner slide assembly, whereupon said load supporting carriage may belowered in the movable upright for causing the load engaging means to beactuated downwardly away from the load engaging member.

References Cited in the file of this patent UNITED STATES PATENTS1,768,149 Remde June 24, 1930 2,702,645 Dempster et a1. Feb. 22, 19552,708,043 Streb et al May 10, 1955 2,921,703 Dempster et a1. Ian. 19,1960

2. IN AN INDUSTRIAL TRUCK HAVING AN OUTER FIXED UPRIGHT MOUNTED AT ONEEND OF THE TRUCK, AN INNER MOVABLE UPRIGHT TELESCOPICAL WITHIN THE OUTERFIXED UPRIGHT, MOTOR MEANS FOR ELEVATING THE MOVABLE UPRIGHT IN THEFIXED UPRIGHT AND A LOAD SUPPORTING CARRIAGE MOUNTED IN THE MOVABLEUPRIGHT FOR RAISING AND LOWERING MOVEMENT RELATIVE THERETO, THECOMBINATION COMPRISING LATCHING MEANS SECURED TO THE MOVABLE UPRIGHT,LOAD ENGAGING MEANS PROJECTING FROM THE LOAD SUPPORTING CARRIAGE, AND ANAUXILIARY UPRIGHT ASSEMBLY MOUNTED ON THE LOAD SUPPORTING CARRIAGE ANDEXTENDING UPWARDLY THEREFROM INCLUDING AN OUTER FIXED ASSEMBLY, AN INNERSLIDE ASSEMBLY HAVING MEANS ENGAGEABLE WITH SAID LATCHING MEANS AND ALOAD ENGAGING MEMBER PROJECTING THEREFROM IN NORMALLY HORIZONTALADJACENT RELATION TO SAID LOAD ENGAGING MEANS, SAID AUXILIARY UPRIGHTASSEMBLY BEING OF SUBSTANTIALLY LESS COLLAPSED HEIGHT THAN SAID OUTERAND INNER UPRIGHTS AND BEING ELEVATABLE IN THE INNER MOVABLE UPRIGHT TOA LOCATION WHEREIN SAID LATCHING MEANS IS ACTUATABLE TO ENGAGE SAIDINNER SLIDE ASSEMBLY, WHEREUPON SAID LOAD SUPPORTING CARRIAGE MAY BELOWERED IN THE MOVABLE UPRIGHT FOR CAUSING THE LOAD ENGAGING MEANS TO BEACTUATED DOWNWARDLY AWAY FROM THE LOAD ENGAGING MEMBER.